HPBP & LPBP
HP Bypass Station 1:- HP/LP bypass system can handel 60% of boiler load. 2:- HPBP valve is a combined pressure reducing and desuperheating station valve 3:- Spray water is tapped from BFP discharge and spray controled by spray control valve. 4:- HPBP dumps the depressurised and desuperheated steam with suitable parameter into CRH line. 5:-Can operate without coordinate with turbine. 6:- Allows quick raising of steam parameters at a level acceptable to turbine for rolling operqtion during start up. 7:-Oil supply unit is installed for operation of HPBP & LPBP valves 8:-Supply oil pressure is maintained at 160 kg/cm2 by the pump and accumulator unit. Modes of HP Bypass Operation 1:- Boiler start-up with TG set at stand still. 2:- Rising of steam parameters to a level acceptable to turbine for rolling. 3:- Turbine start-up and loading while steam flow gets transferred to the turbine 4:- Parallel operation with turbine on load rejection. 5:- Allowing boiler operatio